Chloroacylanilides and a method for the preparation thereof from anilines and chlorocarboxylic acids are disclosed in the German Offenlegungsschift No. 2,027,822, filed on June 7, 1969. This disclosure generically defines a class of compounds which encompasses the compound of the subject invention and describes certain analogues and homologues thereof. However, this publication does not specifically identify the compound of the instant invention and fails completely to recognize its unique character. Surprisingly, it has been found that 2-chloro-N-isopropyl-2',3'-dimethylacetanilide is markedly superior to its closest homologs for the control of undesirable plant species. Moreover, it has been found that said acetanilide compound can be prepared from 3-nitro-o-xylene, an undesirable by-product formed in the manufacture of a recently developed, highly effective, substituted dinitroaniline herbicidal agent. To the present, it has been considered necessary to burn this undesirable byproduct in order to prevent its release into the atmosphere in the vicinity of the manufacturing facility for said herbicidal agent. However, even this measure of ignition of the 3-nitro-o-xylene is less desirable than the conversion of said by-product to a useful herbicide. Obviously, ignition of 3-nitro-o-xylene represents an economic loss in the process of manufacture of the substituted dinitroaniline herbicide and results in the release of oxides of carbon and nitrogen into the atmosphere. With the present invention, it is thus possible to prevent environmental contamination and to provide a highly effective weed control agent utilizing an economically advantageous process, thereby fulfilling a long felt need in the art.
In addition to the German application above-identified, it is further noted that South African Pat. No. 62/3650, dated Aug. 28, 1062, describes alpha-haloacetamides generically as herbicidal agents. As in the German disclosure, the South African patentee does not disclose 2-chloro-N-isopropyl-2',3'-dimethylacetanilide specifically and fails to recognize its unique character.